Machine for straightening gun-barrels.



C. W. SPONSEL.

MACHINE FOR STRAIGHTENING GUN BARRELS. APPLICATION FILED FEB. 28, I916. RENEWED JULY 24.1917.

Patented Sept. 11, 1917.

4 SHEETS-SHEET I.

c. w. SPONSEL. MACHINE'FOR STRAIGHTENING GUN BARRELS.

APPLICATION FILED FEB- 28, I916- RENEWED .IULY 24. 1911- 1,239,538.

Patented Sept. 11, 1917.

4 SHEETS-SHEET 2.

INVENTOR.

A TTORNE Y.

C. W. SPONSEL MACHINE FOR STRAIGHTENING GUN BARRELS. APPLICATION FILED FEB-28,1916. RENEWED JULY 24. 1917.

1 %39,53 3 w Patented Sept. 11, 1917.

4 SHEETS-SHEET 3.

INVENTOR.

A TTORNEY.

C. Wa SPONSEL. MACHINE FOR STRAIGHTENING GUN BARRELS. APPLICATION FILED FEB-28,1916. RENEWED JULY 24.1917. Lfi fi "l. srau nsrarnnr onnroa CHARLES W. SPONSEL, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE SPONSEL COM PANY, CF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

"MACHINE FOR STBAIGHTENING GUN-BARRELS.

Specification of Letters Eatent. Pmbenflmd g m, 111, 1191 X Application filed February 28, 1916, Serial No. 80,959. Renewed July 24., 1917. Serial No. 182,582.

To all whom it my camera: Be it known that 1, CHARLES W. SroNsnL, a citizen ofthe United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Machines for Straightening Gun-Barrels, of which the following is a specification.

.To attain the highest efficiency from the propelling charge and the greatest accuracy in marksmanship the bores of barrels of rifles and machine guns should be as straight as it is possible to make them. During the manufactu e of such barrels when the forged or rolled billets are being bored it frequently happens that owing to variation inthe hardne'ss of the metal and other causes, the drills work out of center and leave the axes of the bores more or less curved between the breeches and mu'zzles. lates to a machine which is designed to detect the slightest defect in, and to remedy such inaccuracy as is indicated in the bore of gun barrels. r

The object of the invention is to provide a simple machine into which gun barrels.

can be quickly placed, tested, straightened, proved and removed, that has means which will electrically indicate the smallest deflections of the bores and mechanically measure the amount of variation from true, and

mechanism which cooperates with the indicating means by which the barrels can be bent and straightened until the inaccuracy indicated by the electrical means and measured by the mechanical means is overcome, thus insuring the greatest possible accuracy in the bores.

The machine illustrated as embodying this invention has centers for supporting a barrel at the breech and muzzle, which centers are mounted so that they may be moved coincidentally longitudinally of the machine.

for carrying the barrel lengthwise back and forth, The centers which are yieldingly held in position are also capable of upward movement so as to allow the ends of the barrel to spring upwardly when it is being bent for straightening it. A strong wire, secured at one end by a fixed clamp, is arranged to be threaded through the barrel and supporting centers, and after its other end is secured by a yielding clamp, be drawn tight This invention reand held taut with a stiff spring tension. The wire clamp supports are mounted so that they may be lowered and raised together a slightdistance and carry the wire down or up, this distance being accurately measurable by a micrometer gage. The wire is connected in an electric circuit containing lamps, and at the middle of the machine is provided with a conducting feeleror contact that is adapted to be engaged with or disengaged from the Wall of the bore of the barrel as the wire is lowered or raised. One of the circuit terminals is connected with the wire, the supports of which are properly insulated, and the other terminal is grounded on the machine. The circuit is so planned that when the wire contact is caused to touch any point along the bore of the barrel the circuit conditions will be changed in such manner that the lamps will show the altered relation, and the gage will show the amount of movement which caused the change. Associated and cooperating with the electrical indicating and mechanical measuring means is mechanism arranged to bend the barrel while in testing position and restore the electrical condition, and thus show a rectification of whatever irregularity is indicated and measured.

Figure 1 of the accompanying drawings shows a front elevation of the machine. Figl 2 shows a plan. Fig. 3 is a diagrammatic illustration of the method of indicating the accuracy of the bore. Fig. -4; is a view of the electrical contact that is threaded through the barrel. Fig. 5 is a face view of the same. Fig. 6 shows an elevation of the machine. Fig. 7 is a vertical section on the plane indicated by the line 7-7 on Fig. 2. Fig. 8 is a vertical longitudinal section through the barrel. Fig. 9. is a sectional view showing the wire clamping and stretching mechanism at the left hand end of the machine. Fig. 10 shows a side view of one of the barrel supporting centers and the adjacent mechanism. Fig. 11 shows a plan of the same. Fig. 12 is a vertical section on the plane indicated by the dotted line 12l2 on Fig. 11. v

The bed 1 of the machine is mounted on acolumn 2 having a widened base 3. A slide 4 is arranged to move back and forth in a guideway that extends from side to side in the top of the bed. On the bottom of this slide is a rack 5 engaging with which is a pinion 6 on a shaft 7 that at the front is provided with a hand wheel 8. A head 9 is adjustably fastened on the top of the slide near each end. Pivoted to each head is an arm 10, and hinged to each arm is a block 11 which holds a tubular barrel supporting center 12. The centers at the top are slotted from end to end and the ends of the centers which project toward each other are tapered. Each arm is pressed downward by a flat spring 13 and each block is pressed forward by a spiral spring 14 and plunger 15. Each block is guided at the front when it moves up and down by a vertical groove in the back surface of the front part of the head. Each center is pushed toward the middle of the machine by a flat spring 16, and the center at the left is arranged to be drawn back by a hand lever 17 that is pivoted to the block and engages with a pin 18 which projects from the cen ter. To put a barrel into the machine the center at the left is drawn back and when one end of the barrel is placed on the center at the right the left center is. allowed to spring-forward into the barrel at that end. When mounted this way the barrel can be moved lengthwise across the machine by turning the hand wheel at the front. The

. heads are located on the slide according to the length of the barrels to be straightened.

The indicator wire 19, which is designed to pass through the barrel and through the barrel supporting centers, is secured at its ends by clamp levers 20 which are pivotally mounted on blocks 21 secured at the ends of rocker arms 22 that project forwardly from a rocker shaft 23 that extends lengthwise of the machine at the back. The rocker shaft is. preferably mounted in fiber bushings 24 placed in brackets 25 attached to the back .of the bed so it can rotate withoutmoving" longitudinally, and will be electrically insulated from the rest of the machine. The clam levers are provided with hand screws 26 w ich, when turned one way, cause the jaw ends of the clamps to bite the ends of the wire against teeth on the clamp blocks, and when turned the other way allow the jaws to open and release the ends of the wire. The clamp block with the clam lever at the left hand end of the machine is slidable horizontally in the end of the arm for tightening the wire. This clamp block has a threaded stem 27 on which turns a hand nut 28. A spring 29 is arranged on the a 22, which carry the wire clamps, to other bending the barrel down at the middle the ends spring up. Thus if the end of a barrel springs up when it is being bent and the center which supports that end of the barrel is lifted, the lever which carries the center holding block engages the bar above it and carries it up. This lifts the wire clamps-so that the wire will not be sheared off or broken by the bending of the barrel.

The rocker shaft has attached to it a lever arm 32 that engages a nut 33 held from rotation by a bracket 34 fastened to the back of the bed. Turning in this nut is the rear end of the arbor 35 on the front end of 'which'is secured the hand wheel 36. Fasindex wheel 58. The index wheel is grad uated on its periphery in thousands of an inch. When the index wheel is turned one Way the nut is drawn forward in such manner as to cause the lever to rock the shaft and turn up the arms and raise the indicator wire. When the index wheel is turned in the opposite direction the nut is moved backward and the weight of the arms and connected parts carries the indicator wire downward. If the thumb screw is loosened the graduated index wheel is released so that it can be turned around and set to zero. As the rocker lever is not attached to the nut, but merely held against it by gravity, the parts are free so that the wire may be lifted whenever the centers are carried up by any bending of a barrel. The lower end of the rocker lever is insulated from the nut by a piece of insulation 39.

Wedge shaped blocks 40 are mounted so that they are free to be moved toward the front and back in slides 41 that are free to be moved along the top of the bed from, side to side. By moving the slides longitudinally of the machine the wedge shaped blocks may be located anywhere that it is desired along the length of the barrel,'and by pushing the blocks backward they may be brought into contact at the required places with the barrel held by the centers. At the center of the machine and projecting forwardly is a bending arm 42 that is pivoted to the bed near the back and at its front end over the center of the barrel is provided with a heavy screw 43 which? may be turned clown or up by hand or by means of a wrench. The rear end of the bending arm is pivotally connected with theupper end of a link 44 that is supported by a link 45 which is jointed to the column. The

then to the lamps.

lower end of the link 44 is connected by a short toggle arm 460 with the bentend of the treadle lever which is pivoted to the base and at the front of the machine is provided with a foot pad 47. When the treadle is depressed, by means of this to gle and link connection the bending arm 1s forced down with great power. ,The treadle may be held down by a lock bar 48 if desired, or

it may be locked up by a safety catch 49.

The treadle is raised bya spring 50 arranged inside of the column; A yielding cushion 51 is attached to the back of the column in such manner as .to prevent the toggle from becoming locked'on center.

Small lamps 52, preferably red and green, are located in a box 53 attached to the front of the bed and adjacent to this is a switch 54. Secured to the back of the bed is a fuse block 55 and attached to the underside is a transformer 56. Line wires are connected with the fuse block which is connected with the switch. The circuit wires run from the switch to the transformer and One end of the circuit is grounded on the machine, while the other end is connected with the indicator wire, the supports of which are, as above described, electrically insulated from the rest of the machine. On the indicator wire at the center of the machine and directly below the bending screw is a conducting feeler or contact 57. The conducting feeler on the wire at the middle of the machine and below the bending screw is arranged so as to always point downward.

In using this machine the ends of the barrel which have been slightly reamed out are placed on the centers with the indicator wire threaded through the barrel and laid in the centers. The free end ofthe wire is then clamped and the wire drawn taut. The barrel may first, if necessary, be rough straightened by rotating it on the centers and moving it along until the highest spot of the bend comes beneath the bending screw. The blocks are moved along to the desired place and pushed back, and then the bending screw is brought down by pressing on the treadle. This may be continued until the barrel is in such condition that the indicator wire will not touch at either end.-

.pushed over until the other end is at the center. The wire is again lowered until the contact engages the bottom of the bore and the light goes out. If the ends are true the index will show zero. The barrel is then turned around to see whether it is mounted true on the center at this end. After this the barrel is pushed along from end to end and rotated to find out where the high spots are, how long the curves are, and the amount of deflection. The barrel is then moved along until the highest point is beneath, the bending screw and the blocks pushed beneath it. The treadle is depressed, bringing down the bending screw and bending the barrel. until with the index at zero the lights will both stay on as the barrel is. rotated. When the barrel can be moved to every position and can be rotated in any position and both lights will stay lighted with the index at zero, it is known that the bore is absolutely straight. As a very small current is employed and the lamps are small and the contact is very delicate, deflections of .0001 of an inch in the barrel will be indicated.

Not only can great accuracy be obtained by this machine. but barrels can be very quickly placed in it or removed from it and rapidly straightened until the desired ac curacy is obtained. By turning down the screw different bends can be made, and by moving the barrel and the bending blocks the bonds can be made in diderent localities. If sufiicient pressure cannot be obtained by the treadle it may be locked down and the bending screw turned down by means of a wrench applied to its upper end. The center heads are readily adjustable for barrels of different lengths and the yielding centers allow the ends of the barrel to spring up when the barrel-is bent intermediate of the'ends. The indicator wire is held with a yielding strain so that if the barrel tends to bend it it will yield sutliciently to prevent its becoming broken, and if the ends of the barrel bend up any great amount the center supporting arms will lift the wire supporting means equally so that the wire will not be sheared or cut 0%. The hollow.

centers are grooved on the top for the full length so that the wire does not have to be threaded through them, and the centers are springpressed so that any change in length between the ends of the barrel as it is bent is compensated for. The electrical contact point and the measuring wheel operate together in complete unison, and the bending and indicating means cooperate to produce an accurate barrel.

The invention claimed is:

1. A machine for straightening gun barrels having means for supporting a barrel, a contact adapted to be engaged with and disengaged from every point along the wall of the bore of the barrel, an electrical circuit connected with said contact, means connected in the electrical circuit for indicating This is repeated said engagement and disengagement of the contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore to the contact and causing such change to be shown by the indicating means.

2. A machine for straightening gun barrels having longitudinally movable means for supporting a barrel, a contact adapted to be engaged with and disengaged from every point along the wall of the bore of the barrel, an electrical circuit connected with said contact, means connected in the electrical circuit for indicating said engagement and disengagement of the contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore to the contact and causing such change to be shown by the indicating means.

3. A machine for straightening gun barrels having means for supporting a barrel, a transversely movable contact adapted to be engaged with and disengaged from every polnt along the wall of the bore of the barrel, an electrical circuit connected with said contact, means connected in the electrical circuit for indicating said engagement and disengagement of the contact with the wall of the bore, and means for bending the barrel and changing'the relation of the wall of the bore to the contact and causing such change to be shown by the indicating means.

4. A machine for straightening gun barrels having longitudinally movable means for supporting a barrel, a transversely movable contact adapted to be engaged with and disengaged from every point along the wall of the bore of the barrel, an electrical circuit connected with said contact, means connected in the electrical circuit for indicating said engagement and disengagement of the contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore to the contfipt and causing such change to be shown by t e indicating means.

5. A machine for straightening gun barrels having means for supporting a barrel, acontact adapted to be engaged with and disengaged from every point along the wall of the bore of the'barrel, an electrical circuit connected with said contact, means connected in the electrical circuit for indicating said engagement and disengagement of the contact with the wall of the bore, means for measuring the amount of relative movement for causing engagement and disenga ement of the contact and the barrel at difi'erent localities in the barrel, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing such change to be shown by the indicating means.

6. A machine for straightening gun barrels having means for supporting a barrel,

a wire adapted to be threaded through the barrel, means for holding the wire taut, means for imparting relative transverse movement between the wire and the barrel, a contact on the wire and adapted to be engaged with every point along the wall of the bore of the barrel, means on the exterior for indicating the engagement gof the contact with and the disengagement of the contact from the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore to the contact and causing such change to be shown by theindicatin means.

7 A machine for straightening gun barrels having means for supporting a barrel, means for moving the barrel supports longitudinally, a wire adapted to be threaded through the barrel, means for holding the wire taut, means for imparting a relative transverse movement between the wire and the vbarrel, a contact on the wire and adapted to be engaged with every point along the wall of the bore of the barrel, means on the exterior for indicating the engagement of the contact'with and the disengagement of the contact from the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing such change to be shown by the indicating means.

8. A machine for straightening gun barrels having means for supporting a barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut, means for moving the wire transversely, a contact on the wire, and adapted to be engaged with every point along the wall of the bore of the barrel,means on the exterior for indicating the engagement of the contact with and the disen agement of the contact from the wall of t e bore,'and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing such change to be shown by the indicating means.

9. A machine for straightening gun barrels having means for supporting a barrel, means for moving the barrel supports longitudinally, a wire adapted to be threaded through the barrel, means for holding the wire taut, means for moving the wire transversely, a contact on the wire and adapted to be engaged with every point along the wall of the bore of the barrel, means on the exterior for indicating the engagement of the contact with and the disengagement of the contact from the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means.

10. A machine for straightening gun bar meaaaa tudinally, a wire adapted to be threaded through the barrel, means for holding the wire taut, means for imparting relative sidewise movement between the wire and the barrel, a contact on the wire and adapted to be engaged with every point along the wall of the bore of the barrel, an electrical circuit connected with said contact, means in said circuit for indicating the engagement of the contact with and the disengagement of the contact from the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means.

11. A machine forstr'aightening gun barrels having means for supporting a barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut, means for moving the wire transversely, a

contact on the .wire and adapted to be engaged with every point along the wall of the bore of the barrel, an electric circuit connected with the contact, means connected in the electric circuit for indicating the engagement of the contact with and the disengage ment of the contact from the wall'of the bore of the barrel, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means. 12. A machine'for straightening gun barrels having means for supporting a barrel,

means for moving the barrel supports longi-,

tudinally, -a wire adapted :to, be threaded through the barrel, means for holding the wire taut, means for moving the wire transversely, a contact on the wire and adapted to be engaged with every point along the wall 40 of the bore of the barrel, an electrical circuit connected with the wire, means in said elecv trical circuit for indicating the engagement of the contact with and the disengagement of the contact from the wall of the bore, and means for bending the barrel and changin the relation of the wall of the bore an the contact and causing said change to be shown by the indicating means.

13. A machine for straightening barrels'havingmeans for supporting a barrel, an electrically alive contact adapted to be located in the hereof the barrel, electrically excited means connected to indicate engagement of said contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means.

14. A machinefor straightening gun barrels having means for supporting'a barrel,

means for moving the barrel supports longitudinally, an electrical contact adapted to be located in the bore of the barrel, electrically excited means arranged to indicate 5 engagement of said contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means.

15. A machine for straightening gun bar- 7a rels having means for su porting a barrel and moving it longitudina 1y, an electrically alive contact adapted to be located in the bore of the barrel, means for moving the electrical contact transversely of the barrel, electrically excited means arranged to indicate the engagement of said contact with the wall of the bore, and means for bending the barrel and changing the relation of the wall of the bore and the contact and causing said change to be shown by the indicating means.

16. A machine for straightening gun barrels having means for supporting a barrel, an electrical circuit, a contact connected in said circuit and adapted to be located inthe an bore of the barrel, an electrical lamp in said circuit arranged to be shunted by the engagement of said contact with the wall of the bore of the barrel, and means for bending the barrel and changing the relation of so the wallof the bore and the contact and causing the lamp to be restored to the circuit.

17. A machine for straightening gun barrels having transversely yielding means for supporting a barrel, a wire adapted to be ea threaded through the barrel, means for holding the wire taut, means for imparting relat1ve transverse movement between the wire and the barrel, a contact on the wire in the barrel, means on the exterior for indicating 1053 the engagement of the contact with and the disengagement of the contact from the wall of the bore of the barrel, and means for bending the barrel.

18. A machine for straightening gun barrels having transversely ylelding means for supporting a barrel, a wire adapted to be threaded through the barrel, transversely .yielding means for holding the wire taut,

means for impartin a relative transverse movement between t e wire and the barrel, a contact on the wire in the barrel, means .on the exterior for indicating the engagement of the contact with and the disengagement of the contact from the wall of the 11115 bore of the barrel, and means for bending the barrel.

19. A machine for straightening gun barrels having transversely yielding means for supporting a barrel, a wire adapted to be threaded through the barrel, transversely yielding means for holdin the wire taut, said wire support bein a apted to be engaged and moved by t e transverse movement of the barrel supports, means for imparting relative transverse movement between the wire and the barrel, acontact'on the wire in the barrel, means on the exterior for indicating the engagement of the contact with and the disengagement of the contact 130 from the wall of the bore of'the barrel, and

' means for bending the barrel.

20. A machine or straightening gun barrels having yielding means for supporting 5 a barrel, a wire adapted to be threaded through the barrel, yielding means for holding the wire taut, means for moving the wire transversely, a contact on the Wire in the barrel, means on the exterior for indicating the engagement of the contact with and the 10 disengagement of the contact from the wall of the bore of the barrel, and means for bending-the barrel.

CHARLES W. SPONSEL. 

